Effect of thrombin peptide 508 (TP508) on bone healing during distraction osteogenesis in rabbit tibia

Thrombin-related peptide 508 (TP508) accelerates bone regeneration during distraction osteogenesis (DO). We have examined the effect of TP508 on bone regeneration during DO by immunolocalization of Runx2 protein, a marker of osteoblast differentiation, and of osteopontin (OPN) and bone sialoprotein (BSP), two late markers of the osteoblast lineage. Distraction was performed in tibiae of rabbits over a period of 6 days. TP508 (30 or 300 μg) or vehicle was injected into the distraction gap at the beginning and end of the distraction period. Two weeks after active distraction, tissue samples were harvested and processed for immunohistochemical analysis. We also tested the in vitro effect of TP508 on Runx2 mRNA expression in osteoblast-like (MC3T3-E1) cells by polymerase chain reaction analysis. Runx2 and OPN protein were observed in preosteoblasts, osteoblasts, osteocytes of newly formed bone, blood vessel cells and many fibroblast-like cells of the soft connective tissue. Immunostaining for BSP was more restricted to osteoblasts and osteocytes. Significantly more Runx2- and OPN-expressing cells were seen in the group treated with 300 μg TP508 than in the control group injected with saline or with 30 μg TP508. However, TP508 failed to increase Runx2 mRNA levels significantly in MC3T3-E1 cells after 2–3 days of exposure. Our data suggest that TP508 enhances bone regeneration during DO by increasing the proportion of cells of the osteoblastic lineage. Clinically, TP508 may shorten the healing time during DO; this might be of benefit when bone regeneration is slow

Colonic complications following human bone marrow transplantation

Background: Human bone marrow transplantation (BMT) becomes an accepted treatment of leukemia, aplastic anemia, immunodeficiency syndromes, and hematologic malignancies. Colorectal surgeons must know how to determine and manage the main colonic complications. Objective: To review the clinical features, clinical and pathological staging of graft vs host disease (GVHD), and treatment of patients suffering with colonic complications of human bone marrow transplantation. Patients and methods: We have reviewed the records of all patients that received an allogeneic bone marrow transplant and were evaluated at our Colon and Rectal Surgery department due to gastrointestinal symptoms, between January 2007 and January 2012. The study was carried out in patients who developed colonic complications, all of them with clinical, histopathological or laboratory diagnosis. Results: The study group was constituted by 77 patients, 43 male and 34 female patients. We identified colonic complications in 30 patients (38.9%); five patients developed intestinal toxicity due to pretransplant chemotherapy (6.4%); graft vs. host disease was present in 16 patients (20%); 13 patients (16.8%) developed acute colonic GVHD, and 3 (3.8%) chronic GVHD. Infection was identified in 9 patients (11.6%). Conclusions: The three principal colonic complications are the chemotherapy toxicity, GVHD, and superinfection; the onset of symptoms could help to suspect the type of complication (0–20 day chemotherapy toxicity, 20 and more GVHD), and infection could appear in any time of transplantation. Resumo: Experiência: O transplante de medula óssea humana (MOH) passou a ser um tratamento adotado para leucemia, anemia aplástica, síndromes de imunodeficiência e neoplasias hematológicas. Cirurgiões colorretais devem saber como determinar e tratar as principais complicações do cólon. Objetivo: Revisar as características clínicas, estadiamentos clínico e patológico da doença do enxerto versus hospedeiro (DEVH) e o tratamento de pacientes padecendo com as complicações colônicas do transplante de medula óssea humana. Pacientes e Métodos: Revisamos os registros de todos os pacientes que receberam um transplante de medula óssea alogênica e foram avaliados em nosso Departamento de Cirurgia do Cólon e Reto em função de sintomas gastrointestinais, entre janeiro de 2007 e janeiro de 2012. O estudo teve por base os pacientes que desenvolveram complicações do cólon, todos com diagnóstico clínico, histopatológico ou laboratorial. Resultados: O grupo de estudo foi constituído por 77 pacientes, sendo 43 homens e 34 mulheres. Identificamos complicações do cólon em 30 pacientes (38,9%); cinco pacientes exibiam toxicidade intestinal por quimioterapia antes do transplante (6,4%); DEVH estava presente em 16 pacientes (20%), 13 pacientes (16,8%) foram acometidos por DEVH colônica aguda três pacientes (3,8%) DEVH crônica. Infecção foi detectada em 9 pacientes (11,6%). Conclusões: As três principais complicações do cólon são: toxicidade por quimioterapia, DEVH e superinfecção. O surgimento dos sintomas poderia ajudar a levantar suspeitas sobre o tipo de complicação (0–20 dias, toxicidade por quimioterapia; 20 ou mais dias, DEVH). Infecções podem ocorrer em qualquer momento do transplante. Keywords: Colonic complications, Human bone marrow transplantation, Superinfection, Palavras-chave: Complicações do colo, Transplante de medula óssea humana, Superinfecçã